Planetary type body for printer



y 1964 B. HOWARD PLANETARY TYPE BQDY FOR PRINTER 2 Sheets-Sheet 1 Filed Sept. 1, 1960 INVENTOR. fiemard Howard %4 M ATTORNEYS July 21, 1964 B. HOWARD 3,141,402

PLANETARY TYPE BODY FOR PRINTER Filed Sept. 1, 1960 2 Sheets-Sheet 2 R/ g B T 5.1:. E. f5. 1:. 7.

INVENTOR.

Ear/70m Howard A True/W575 United States Patent Ofice 3,141,4fi2 Patented July 21, 1964 3,141,402 PLANETARY TYPE BODY FOR PRINTER Bernard Howard, Upper Saddle River, NJ, assignor, by mesne assignments, to Mite Corporation, New Haven, Conn, a corporation of Delaware Filed Sept. 1, 1960, Ser. No. 53,475 16 Claims. (Cl. 10193) This invention relates to rotary type bodies, such as a type wheel or type cylinder, and to the associated mechanism driving the same.

The primary object of the invention is to generally improve printers which print on the fly, that is, in which a rotary type body rotates continuously, and the paper in front of which is struck by a hammer at the exact instant that a desired letter faces the hammer.

Another object is to provide a rotary print head capable of high speed operation which does not have one of the salient, inherent weaknesses of such type heads. On such high speed type heads the problem is to time the hammer stroke so that it not only meets the character to be printed, but meets it at precisely the instant when that character is parallel to the surface of the recording medium and the hammer face. Failing this, only the upper or the lower portions of a character may be printed. In some high speed rotary printers the problem is met with fairly elaborate electronic circuitry and ultra high speed mechanisms to provide as nearly as possible the perfect timing required to make a legible character.

In the present printer, each character of the type body is engraved or mounted on an element turned by a planet gear. The planet gears are assembled around a sun gear in such a way that the rotation of the entire assembly always keeps the face of all of the characters parallel to the recording medium and hammer. In the disclosed structure the elements turned by the planet gears are rods, so that printing simultaneously in a number of columns is possible by using a number of hammers.

In accordance with my invention the planet gear mounting of the characters keeps the type faces parallel to the recording medium at all times. Therefore, errors in timing of the hammer stroke will not render the character illegible, but will, at worst, disturb the alignment of the characters one to the next, but still render them completely readable.

In accordance with a further object of the invention, the location of characters side by side along rods permits the spacing of successive characters along the printed line very close to one another, since there is no need to have individual mechanisms and mountings for a series of type wheels side by side.

To accomplish the foregoing general objects, and other;

more specific objects which will hereinafter appear, my invention resides in the rotary printer mechanism, and the elements thereof and their relation one to another, as are hereinafter more particularly described in the following specification. The specification is accompanied by drawings in which:

FIG. 1 is a perspective schematic view explanatory of the invention;

FIG. 2 is a partially sectioned end view, shown in similar schematic form, and taken approximately in the plane of the stepped line 22 of FIG. 1;

FIG. 3 is a front elevation;

FIG 4 is a section taken in the plane of the line 44 of FIG. 2;

FIG. 5 is a fragmentary section explanatory of the operation of the printer; and

FIGS. 6 and 7 are explanatory of one advantage of the printer.

Referring to the drawing, the rotary printer comprises a hammer 12 and a rotary type body generally designated 14. This carries about its periphery a plurality of type elements 16, 18, 20, 22, etc., which are rotatably mounted on the body 14. There is also gearing for rotating the body 14, and for rotating the elements (16, 18, etc.) in such relation that a type element facing the plane of the hammer face or the plane of the paper remains facing the hammer as the body 14 rotates. More specifically, there is planetary gearing including an orbit gear 24 secured to or forming a part of the body 14, a sun gear 26 coaxial with the body, and planet gears 28 secured to the type elements.

A motor 30 with reduction gearing 31 drives the type body 14, and in the present case it first drives a gear 32 meshing with the orbit gear 24. There is also additional gearing connecting the orbit gear 24 to the sun gear 26, and so to the planet gears 28. More specificially, in the present case the orbit gear 24 meshes with a pinion 36 on a jack shaft 38. The jack shaft carries a gear 40 secured thereto and meshing with a gear 42, which in turn is integral or secured or keyed to the sun gear 26 for rotation therewith.

Referring now to FIG. 5, a sheet of paper or other medium being printed is indicated by the broken line 51 The means to move the same is not shown, but it may be assumed to move upward. It passes between the rotary type body 14, on one side, and the ink ribbon 116 and hammer 12, on the other side. In FIG. 5 a type character is formed on a flat 52 forming a part of a type element 16. Similarly a type character is formed on a flat 54 of type element 20, and another character is formed on the flat 56 of type element 24. The planet gears 28 are secured to the type elements, and they mesh with sun gear 26. From the position of the flats 52, 54, and 56, it will be seen that the characters remain parallel to the paper 50 as the type body rotates. As a convenient expression it may be said that the type elements face the plane of the hammer and remain facing the plane of the hammer as they rotate. This is also shown in FIG. 2, but to a smaller scale and therefore not as clearly.

The benefit of this may be explained with reference to FIGS. 6 and 7 of the drawing. If a type character is fixed as usual on the type body, it turns through an angle as the body rotates. In FIG. 6 the hammer 12 has struck the paper 50 (and/or an ink ribbon or carbon paper 116 in accordance with conventional practice) at exactly the right instant to print all of the letter B from top to bottom, as is indicated at 60. If the hammer strikes a little too soon, the character will be at a slight angle, with the upper part away from the paper, and consequently only the lower part of the character will be printed as indicated at 62. If the hammer strikes the paper an instant too late only the upper part of the character will be printed as indicated at 64. With many of the characters of the alphabet, this leads to indefiniteness and uncertainty in reading the same. For example, at 64 the B could be read as R. 7

However, with the present invention the character remains parallel to the paper at all times. Correct timing of the hammer will produce the character shown at 66; a slightly early timing will produce the character shown at 68; and a slightly delayed timing will produce the character shown at 70. The latter two are slightly above or below the line, but the entire character has been printed and is fully legible.

Reverting now to FIGS. 1-5 of the drawing, the mechanism preferably comprises two axially spaced sun gears 26 and 126 which rotate together. In the present case they are both secured to a common shaft 72 which is coaxial with the type drum and orbit gear 24. This is simpler than duplicating the drive gearing at both ends although that may be done. The planet gears 28 are as there are characters).

secured to alternate elements 16, 20, 24, etc., and mesh with the sun gear 26. The planet gears 128 of the intermediate elements 18, 22, etc. mesh with the other sun gear 126. In this way the planet gear of any one element, say element 18, does not interfere with the planet gears of the adjacent elements 16 and 20, and the planet gears may be larger in diameter than the type elements 16, 18, etc.

As so far described the type body might be a type wheel carrying only one ring of characters. This would be usable with a tape or a sheet of paper which is bodily moved step by step sideward relative to the type body and hammer. Conversely, when dealing with a sheet of paper, the wheel and hammer may be moved sideward step by step relative to the sheet. However, the invention is also applicable to a type body in the form of a cylinder which may be as long as the paper is wide.

Such an arrangement is here illustrated, and referring to FIGS. 1 and 3, the type body 14 is a cage-like body in the form of a cylinder, and the type elements 16, 18, etc. are in the form of rods. Each rod has characters along one side, as will be seen in FIGS. 1 and 3, and the same character appears along the entire length of a single rod. The sun gear 26 is located outside one end of the type body, and the sun gear 126 is located outside the other end of the type body, so that the planet gears 28 are at one end, and the planet gears 128 are at the other end. This provides maximum clearance between the planet gears 28 on the one hand, and the planet gears 128 on the other.

The cage may consist of only the two ends 24 and 124, in which case they are preferably driven in unison, and for this purpose the ends 24 and 124 act also as like orbit gears, driven by like jack shaft pinions 36 and 136, both carried on the jack shaft 38.

The timing of the operation of the hammer in relation to a selected character may be controlled in varied ways, and in the present case an electrical distributor is associated with a keyboard. More specifically, there is a stationary distributor 74 (FIGS. 1, 2 and 3) having a ring of electrical contacts 76. These correspond in number and spacing to the type elements around the type body, and they are engaged by a contactor 78 carried by the shaft 80 which also carries the gear 32. It is for this reason that the gear 32 preferably has the same number of teeth as the orbit gear 24, so that shaft 80 may be used to rotate the contactor 78 in one-to-one unison with the type body.

Electrical current is supplied from a suitable source 82 (FIG. 1). This is connected by a conductor 84 to all of the keys 86, 88, 90, etc. (there being as many keys The keys when depressed serve to close individual contacts 92, 94, 96, etc. connected by conductors to corresponding contacts 76 on the stationary distributor 74. Current then flows through contactor 78, brush 98, and wire 100, to a solenoid 102 which pulls a link 104 to operate the hammer arm 106. The latter is pivoted at 108 and is normally retracted by a spring 110. The electrical circuit is completed through conductor 112. The reduction gear motor 30 runs continuously.

With this arrangement depression of a key causes the hammer to operate at a time determined by the distributor 74, and this is properly related to the characters on the rotating type body. Initial registration may be adjusted, as by means of an adjusting knob 114 connected to the distributor 74, and in practice the adjustment may be locked in position by appropriate lock means, and may be aided by worm and gear reduction or equivalent refinement to facilitate fine adjustment of the timing of the hammer.

The paper 50 and the ink ribbon 116 have been omitted from FIGS. 1 and 3 for clarity, but are shown in FIGS. 2 and 5 of the drawing.

The means for shifting the print step by step along a line is not shown in the drawing, and may be of conventional character. In one arrangement the hammer arm 106 is advanced step by step relative to the type body and the paper. For this purpose it is moved by a cable or tape or lead screw operated intermittently through a pawl and ratchet mechanism, and the return movement of the hammer may operate the pawl to cause it to advance the hammer another step. The hammer remains stationary during its forward or printing stroke, that is, it prints between steps.

In a different known arrangement there are as many hammers along the type body as there are characters, there being one hammer for each character. An appropriate distributor switches the hammer operating current from one hammer to the next down the row. A third method which provides the highest speed operation again employs one hammer for each character, and the circuitry is so set up that all of the columns or points along a line in which A is to be printed have their hammers tripped simultaneously at the A position, and all those where B is to be printed are tripped simultaneously when the type drum reaches the B position, and so on. This method requires only one rotation of the type drum, but of course it requires a complex line-at-a-tirne signal input to the printer, rather than a manually operated keyboard or a one character input.

One specific example of gearing which may be used for the present purpose employs orbit gears 24 and 124 each having teeth at a pitch diameter of approximately 2.250 inches; two sun gears 26 and 126 each having 192 teeth at a pitch diameter of 1.600 inches; 32 planet gears 28 and 128 each having 32 teeth at a pitch diameter of 0.266 inch; two jack shaft gears 36 and 136 each having 24 teeth at a pitch diameter of approximately 0.343 inch; and a jack shaft gear 40 having 28 teeth at a pitch diameter of 0.343 inch. The gear 42 has the same number of teeth as the orbit gears 24 and 124 and a pitch diameter of 2.207. The gear 32, when used to also drive a distributor as here shown, has the same number of teeth and pitch diameter as the orbit gears.

It will be understood that these quantitative values are given by way of illustration, and not in limitation of the invention.

Although I have referred to printing on the fly (continuous rotation of the type body) it will be understood that the type body may be turned intermittently by suitable selector mechanism, and may dwell or come to rest while being struck by the print hammer. The advantage shown in FIG. 7 will apply because it will take care of any slight error in the angular rotation or dwell position of the type body. Of course, the problem is more acute in the case of a type body which is continuously rotated.

It is possible to omit the sun gear 126 and the planets 128 provided that all of the planets mesh with the sun gear 26, that is, if all are at one end.

Also the shaft 72 connecting the two sun gears 26 and 126 may be omitted if the type elements each have planet gears at both ends designed to mesh with both sun gears 26 and 126. In other words rotation may be transmitted from one sun gear 26 to the other sun gear 126 by means of the elements 16, 18, etc., with pinions on both ends of each element.

It is believed that the construction and operation of my improved planetary type body, as well as the advantages thereof, will be apparent from the foregoing detailed description. It will also be apparent that, while I have shown and described the invention in a preferred form, changes may be made in the structure shown without departing from the scope of the invention, as sought to be defined in the following claims. In the claims the term plane of the hammer face means the plane that it has at the printing station.

I claim:

1. A rotary printer comprising a hammer, a rotary type body carrying about its periphery a plurality of type elements which are rotatably mounted on the body for rotation relative to the body, an orbit gear for rotating the body, two axially spaced sun gears coaxial with the orbit gear, a planet gear connected to each of said elements, the planet gears of alternate elements meshing with one of said sun gears, the planet gears of the intermediate elements meshing with the other of said sun gears, whereby the planet gear of an element does not interfere with the planet gears of the adjacent elements, and additional gearing connecting the orbit gear to the sun gears and so to the planet gears in such relation that a type element remains facing the hammer plane of the face the body rotates.

2. A rotary printer comprising a hammer, a rotary type body carrying about its periphery of plurality of type elements which are rotatably mounted on the body for rotation relative to the body, an orbit gear for rotating the body, two axially spaced sun gears coaxial with the orbit gear, one sun gear being located on one side of the type body and the other being located on the other side of the type body, a planet gear connected to each of said elements, the planet gears of alternate elements meshing with one of said sun gears, the planet gears of the intermediate elements meshing with the other of said sun gears, whereby the planet gear of an element does not interfere with the planet gears of the adjacent elements, and additional gearing connecting the orbit gear to the sun gears and so to the planet gears in such relation that a type element remains facing the plane of the hammer face as the body rotates.

3. A rotary printer comprising a hammer, a rotary type body in the form of a cylinder carrying about its periphery a plurality of type elements in the form of rods which are rotatably mounted on the body for rotation relative to the body, each rod having a line of characters along one side of the rod, an orbit gear for rotating the body, two axially spaced sun gears coaxial with the orbit gear, planet gears secured to said elements, the planet gears of alternate elements meshing with one sun gear, and the planet gears of the intermediate elements meshing with the other sun gear, whereby the planet gears do not interfere with the planet gears of adjacent elements, and additional gearing connecting the orbit gear to the sun gears and so to the planet gears in such relation that a type element remains facing the plane of the hammer face as the body rotates.

4. A rotary printer comprising a hammer, a rotary type body in the form of a cylinder carrying about its periphery a plurality of type elements in the form of rods which are rotatably mounted on the body for rotation relative to the body, each rod having a line of characters along one side of the rod, an orbit gear for rotating the body, two axially spaced sun gears coaxial with the orbit gear, one sun gear being located outside one end of the body and the other being located outside the other end of the body, planet gears secured to said elements, the planet gears of alternate elements being located at one end of the body and meshing with one sun gear, and the planet gears of the intermediate elements being located at the other end of the body and meshing with the other sun gear, whereby the planet gears do not interfere with the planet gears of adjacent elements, and additional gearing connecting the orbit gear to the sun gears and so to the planet gears in such relation that a type element remains facing the plane of the hammer face as the body rotates.

5. A rotary printer as defined in claim 2 in which there is a motor for continuously rotating the type body, means to operate the hammer, and a manually operable keyboard for causing the said means to operate the hammer in suitably timed relation to engage a selected one of the type elements.

6. A rotary printer as defined in claim 4 in which there is a motor for continuously rotating the type body, means to operate the hammer, and a manually operable keyboard for causing the said means to operate the hammer in suitably timed relation to engage a selected one of the type elements.

7. A rotary printer as defined in claim 2 in which there is a motor for continuously rotating the type body, an electrical distributor the rotating portion of which is driven by said motor in unison with the type body, said distributor having contacts corresponding to the type elements of the type body, a signal source for energizing one contact or another of said distributor, means to operate the hammer, and circuitry controlled by said distributor for causing said means to operate the hammer in suitably timed relation to engage a selected one of the type elements.

8. A rotary printer as defined in claim 4 in which there is a motor for continuously rotating the type body, an electrical distributor the rotating portion of which is driven by said motor in unison with the type body, said distributor having contacts corresponding to the type elements of the type body, a signal source for energizing one contact or another of said distributor, means to operate the hammer, and circuitry controlled by said distributor for causing said means to operate the hammer in suitably timed relation to engage a selected one of the type elements.

9. A rotary printer as defined in claim 2 in which there is a motor for continuously rotating the type body, an electrical distributor the rotating portion of which is driven by said motor in unison with the type body, said distributor having contacts corresponding to the type elements of the type body, a manually operable keyboard for energizing one contact or another of said distributor, means to operate the hammer, and circuitry controlled by said distributor for causing said means to operate the hammer in suitably timed relation to engage a selected one of the type elements.

10. A rotary printer as defined in claim 4 in which there is a motor for continuously rotating the type body, an electrical distributor the rotating portion of which is driven by said motor in unison with the type body, said distributor having contacts corresponding to the type elements of the type body, a manually operable keyboard for energizing one contact or another of said distributor, means to operate the hammer, and circuitry controlled by said distributor for causing said means to operate the hammer in suitably timed relation to engage a selected one of the type elements.

11. A rotary printer comprising a hammer, a rotary type body carrying about its periphery a plurality of type elements having a single type face and which are rotatably mounted on the body for rotation relative to the body, means for rotating the body, gearing continuously interconnecting the body and the elements for rotating the elements relative to the body in such relation that the type face of a type element remains facing the plane of the hammer face as the body rotates, a motor for continuously rotating the type body, means to operate the hammer, and a manually operable keyboard for causing the said means to operate the hammer in suitably timed relation to engage a selected one of the type elements.

12. A rotary printer comprising a hammer, a rotary type body in the form of a cylinder carrying about its periphery a plurality of type elements in the form of rods which are rotatably mounted on the body for rotation relative to the body, each rod having a line of characters along one side of the rod, an orbit gear secured to the body, a sun gear coaxial with the orbit gear, planet gears secured to the rods for rotating the same, additional gearing connecting the orbit gear to the sun gear and so to the planet gears in such relation that the side of a rod having the line of characters remains facing the plane of the hammer face as the body rotates, all of said gearing remaining continuously in mesh, a motor for continuously rotating the type body, means to operate the hammer, and a manually operable keyboard for causing the said means to operate the hammer in suitably timed relation to engage a selected one of the type elements.

13. A rotary printer comprising a hammer, a rotary type body carrying about its periphery a plurality of .type elements having a single type face and which are rotatably mounted on the body for rotation relative to the body, means for rotating the body, and gearing continuously interconnecting the body and the elements for rotating the elements relative to the body in such relation that the type face of a type element remains facing the plane of the hammer face as the body rotates, a motor for continuously rotating the type body, an electrical distributor the rotating portion of which is driven by said motor in unison with the type body, said distributor having contacts corresponding to the type elements of the type body, a signal source for energizing one contact or another of said distributor, means to operate the hammer, and circuitry controlled by said distributor for causing said means to operate the hammer in suitably timed relation to engage a selected one of the type elements.

14. A rotary printer comprising a hammer, a rotary type body in the form of a cylinder carrying about its periphery a plurality of type elements in the form of rods which are rotatably mounted on the body for rotation relative to the body, each rod having a line of characters along one side of the rod, an orbit gear secured to the body, a sun gear coaxial with the orbit gear, planet gears secured to the rods for rotating the same, additional gearing connecting the orbit gear to the sun gear and so to the planet gears in such relation that the side of a rod having the line of characters remains facing the plane of the hammer face as the body rotates, all of said gearing remaining continuously in mesh, a motor for continuously rotating the type body, an electrical distributor the rotating portion of which is driven by said motor in unison with the type body, said distributor having contacts corresponding to the type elements of the type body, a signal source for energizing one contact or another of said distributor, means to operate the hammer, and circuitry controlled by said distributor for causing said means to operate the hammer in suitably timed relation to engage a selected one of the type elements.

15. A rotary printer comprising a hammer, a rotary type body carrying about its periphery a plurality of type elements having a single type face and which are rotatably mounted on the body for rotation relative to the body, means for rotating the body, and gearing continuously interconnecting the body and the elements for rotating the elements relative to the body in such relation that the type face of a type element remains facing the plane of the hammer face as the body rotates, a motor for continuously rotating the type body, an electrical distributor the rotating portion of which is driven by said motor in unison with the type body, said distributor having contacts corresponding to the type elements of the type body, a manually operable keyboard for energizing one contact or another of said distributor, means to operate the hammer, and circuitry controlled by said distributor for causing said means to operate the hammer in suitably timed relation to engage a selected one of the type elements.

16. A rotary printer comprising a hammer, a rotary type body in the form of a cylinder carrying about its periphery a plurality of type elements in the form of rods which are rotatably mounted on the body for rotation relative to the body, each rod having a line of characters along one side of the rod, an orbit gear secured to the body, a sun gear coaxial with the orbit gear, planet gears secured to the rods for rotating the same, and additional gearing connecting the orbit gear to the sun gear and so to the planet gears in such relation that the side of a rod having the line of characters remains facing the plane of the hammer face as the body rotates, all of said gearing remaining continuously in mesh, a motor for continuous- 1y rotating the type body, an electrical distributor the rotating portion of which is driven by said motor in unison with the type body, said distributor having contacts corresponding to the type elements of the type body, a manually operable keyboard for energizing one contact or another of said distributor, means to operate the hammer, and circuitry controlled by said distributor for causing said means to operate the hammer in suitably timed relation to engage a selected one of the type elements.

References Cited in the file of this patent UNITED STATES PATENTS 2,093,545 Bryce et al. Sept. 21, 1937 2,210,021 Breitling et al. Aug. 6, 1940 2,328,638 Fuller et a1. Sept. 27, 1943 2,613,795 Yutang Oct. 14, 1952 2,627,807 Buhler et al Feb. 10, 1953 2,776,618 Hartley Jan. 8, 1957 2,825,279 Gottscho Mar. 4, 1958 2,919,641 Pileger Jan. 5, 1960 

1. A ROTARY PRINTER COMPRISING A HAMMER, A ROTARY TYPE BODY CARRYING ABOUT ITS PERIPHERY A PLURALITY OF TYPE ELEMENTS WHICH ARE ROTATABLY MOUNTED ON THE BODY FOR ROTATION RELATIVE TO THE BODY, AN ORBIT GEAR FOR ROTATING THE BODY, TWO AXIALLY SPACED SUN GEARS COAXIAL WITH THE ORBIT GEAR, A PLANET GEAR CONNECTED TO EACH OF SAID ELEMENTS, THE PLANET GEARS OF ALTERNATE ELEMENTS MESHING WITH ONE OF SAID SUN GEARS, THE PLANET GEARS OF THE INTER- 